Alternating current or like motor with gyratory armature



March 16,1948". A, E, ADAMS TAL `-2374i ALTERNATING CURRENT OR LKE MOTOR WITH GYRATORY ARMATURE Filed. April 24@ 1945 Uil/017 l r Patented Mai'. 16, 1948 ALTERNATING CURRENT R LIKE MGTOR WITH GYRATORY ARMATURE Albert Ernest Adama and Dmitri Waloff, Wells,

England, assigner: to Scophony Limited, London, England Application April 24, 1946, Serial No. 684,480 In Great Britain January 12, 1945 l l1 Claims.

The present invention relates tc dynamo-electric devices and particularly to small electric motors adapted to operate from alternating or pulsating current.'

The present invention has amongst its objects to provide a-small motor having relatively high efficiency and a high torque for a given size. A further object is to provide a motor adapted to run synchronously from an alternating or pulsating supply in which relatively low speeds of rotation can be obtained without the need for parts rotating in bearings at relatively high speeds.

According to the present invention a dynamoelectric device comprises a first member mounted for gyratory motion, a second member mounted for rotation relatively to said first member and in rolling engagement with said first member and electromagnetic means for imparting gyratory motion to said first member to produce relative rotation between said iirst and second members.

1n a preferred form of the present invention, the said first member is mounted for gyratory motion in a conical path but is prevented from rotation, the said second member is mounted for rotation and is in frictional or toothed engagement with a part of the said first member winch moves in a circular path. The point on the said first member which lies at the apex of the cone is preferably mounted upon a flexible support which permits limited gyration but prevents rotation.

The invention will be described by way of example with reference to the accompanying drawing in which Figs. 1 and 2 show diagrammatically and in part sectional elevation two embodiments of the invention,

Fig. 3 is a view in sectional elevation of a preferred embodiment of the invention,

Fig. i is a view in section on the line 4 4 of Fig. 3,

Fig. 5 shows a wiring diagram for the coils of Figs. 3 and 4,

Fig. 6 is a view in sectional, elevation oi' a further preferred embodiment oi the invention. and

Fig. 7 is a view in section along the line 6-8 in Fig. 5. that is to say an end view of the device with the right hand end portion removed.

Like parts in the several figures are given the same references.

Referring to Fig. 1. a first member constituted by a cylindrical rod III is fixed at one end to the centre of a diaphragm II and projects perpendicularly therefrom. The edge of the diaphragm is fixed to a support I2. The external surface at the free end of the rod Il) rests upon a corresponding internal surface within a cylindrical recess I3 in a member Il mounted for rotation in a bearing in a support I5. The diameter of the recess I3 is greater than that of the rod III. Intermediate the ends of the rod is fixed an armature I8 co-operating with an electromagnet system i1 adapted to produce, when fed with alternating or pulsating current, a magnetic field which rotates about the armature. The armature may be provided with polarislng windings or it may be a permanent magnet.

When the rotating magnetic field is set up, the armature I6 is caused to? move in a circular path limited by the engagement of the rod I0 in the recess I3. The rod Ib thus moves in a conicai path, the diaphragm II being at the apex of the cone and preventing rotation of the rod about its axis. This gyratory motion of the rod i0 causes the rotatably mounted member to rotate owing to friction between the rod and the cylindrical wall of the recess i3. The gear ratio between the rotation of the rotatable member and the gyrations of the rod `will thus be equal to where D and d are the diameters of the recess i3 and the rod I 0 respectively. The free end of the rod may be provided with teeth engaging internal teeth on the rotatably mounted member.

In the embodiment shown in Fig. 2 a diaphragm il of magnetic material is fixedly mounted above a number of pole pieces I1 provided with energising coils. The diaphragm Il is supported by a cup-shaped member I8 of magnetic material which acts as a yoke for the pole pieces Il. There may for example be four pole pieces and coils and suitable air gaps are provided between the diaphragm II and the pole pieces i1. A rod I0 is fixed to the centre of the diaphragm II and projects perpendicularly therefrom, downwards between the pole pieces I1. Its free end engages loosely in a cylindrical recess I3 in a member I4 mounted for rotation in a bearing in a support I5 relatively to the pole pieces and diaphragm.

The energising coils are so connected to a source of alternating or pulsating current that they reach their maxima in succession so that a ripple is caused to pass around the diaphragm thus causing the rod III to move in a conical path and drive the rotatable member |4 asin the .first example.

Referring to Figs. 3 and 4, a casing comprises two cylindrical portions I3 and 20 having between them the edge of a diaphragm Il, and two end plates 2| and 22 in which a shaft 23 is mounted in ball bearings 24 and 25. The casing is held together and clamps the diaphragm i in posi tion by suitable means not shown. On the shaft 23 is fixed a rotatable member I4 vhaving a backwardly turned fiange 28. Fixed through the centre of the diaphragm. ii is a gyratory member l0, in this casein the forml of a tube of suitable magnetic material, permanently magnetised to north polarity at one end and south polarity at the other end. At one end of the member l0 is a iiange 21 of diameter slightly less than that of the inside of the ange 28. On each side of the diaphragm is provided a pair of laminated pole pieces I1 having windings 23 and 23 and 30 and 3| respectively. Each pair of diametrically opposite pole pieces has a laminated annular yoke 32. The windings may be connected as shown in Fig. 5 to terminals 33 for connection to a single phase alternating current supply. A switch 34 and condenser 35 are provided whereby in one setting of the switch shown in full lines the windings 30 and 3| are placed directly across the terminals 33 and the windings 23 and 23 are in series with the condenser 35 across these terminals, whilst in the dotted setting of the switch 34 the condenser 35 is in series with the windings 30 and 3| and the windings 23 and 29 are connected directly across the terminals 33. In both settings of the switch 34 the current in the two pairs of windings are phase displaced by approximately 90 relatively to one another and by operating the switch the direction of gyration of the member i0 and hence that of.rota tion of the shaft 23 can be changed.

Owing to the relatively large diameters D and d of the contacting surfaces of the members 26 and 21 compared with the difference between their diameters, the ratio between the speed of gyration of the member l0 and the speed of rotation of the shaft 23 is high. Where it is desired that the gear ratio should :be exactly maintained, teeth are provided upon the engaging surfaces of the members 26 and 21. In order to prevent exless to limit the radius of gyratory movement of the member i0, the member I4 may be provided with a boss 36 engaging in the hollow end of the member l0 with sufficient play to provide the desired radius of rotation. Alternatively, in order to reduce frlctional losses, the fiange 26 of the member i4 may be provided with a rolling surface of radius equal to that of the pitch circle of the teeth and the member 21 may be provided with a correspending surface adapted to roll on the first named surface, the dierence in radii of these surfaces being such as to give the desired radius of gyratory motion.

In order to avoid the need for phase-splitting, as shown in Fig. 5, and to simplify the construction, the arrangement shown in Figs. 6 and 7 may be used. Only one pair of windings 28 and 29 is used and the diaphragm is cut away as shown in Fig. '1 tb form a diametral bridge portion 31 which is inclined relatively to the axis of the windings 28 and 29. These windings when energised by single phase alternating current serve motion of the member lto a gyratory one in an mounted for rotation relatively to said first member and in rolling engagement with a part of said first member which moves in a circular path, and electromagnetic means for imparting gyratory motion to said first member to produce relative rotation between said first and second members.

2. A dynamo-electric device comprising a first member mounted upon a flexible support which permits gyration but prevents rotation of said first member relatively thereto, a first frictional driving surface in the form of a surface of revolution on said first member, a second member mounted for rotation relatively to said first member and having a second frictlonal driving surface in rolling engagement with said first frictlonal driving surface, and electromagnetic means for imparting gyratory motion to said first member to to impart to the member I0 alternating force in produce relative rotation between said first and second members.`

l 3. A dynamo-electric device comprising a first member mounted upon a flexible support which permits gyration -but prevents rotation of said first member relatively thereto, an external frictional driving surface in the form of a surface of revolution on said first member, a second member mounted for rotation relatively to saidfirst member and having an internal frictional driving surface in rolling engagement with said external irictional driving surface, and electromagnetic means for imparting gyratory motion to said first member to produce relative rotation between said iirst and second members.

4. A dynamo-electric device comprising a first member mounted upon a iiexible support which permits gyration but prevents rotation of said first member relatively thereto, a toothed portion on said first member, a second member mounted for rotation relatively to said first member and having a toothed portion in rolling engagement with the toothed portion of said first member, and electromagnetic means for imparting gyratory motion to said first member to produce relative rotation between said first and second members.

5. A dynamo-electric device comprising a frame, a diaphragm having its periphery fixed to said frame, a first member fixed to substantially the centre of said diaphragm whereby said first member is free to gyrate in a conical path but prevented from rotation relatively to said frame, a second member mounted on said frame for rotation reiatively thereto and having a surface which is in rolling engagement with said first member, and electromagnetic means for` imparting gyratory motion to said first member to produce relative rotation between said rst and second members.

6. A dynamo-electric machine according to claim 5, wherein said electromagnetic means are arranged to apply pulsating force to said first member in a direction substantially perpendicular to the axis of said gyration and wherein said diaphragm is so constituted as to cause said first member to move in a substantiallyy conical path in response to said pulsating force.

r 7. A dynamo-electric device comprising a first member mounted for gyratory motion, a second member mounted for rotation relatively to said iirst member and in rolling engagement with said iirst member and electromagnetic means for imparting gyratory motion to said first member to produce relative rotation between said ilrst and second members, characterised in that said electromagnetic means comprise a magnetic circuit of magnetic material constituted in part by said first member, a winding upon a part of said magnetic circuit for generating a pulsating magnetic ux in said magnetic circuit, and means for generating. a unidirectional magnetic flux in said magnetic circuit including said part.

8. A dynamo-electric device comprising a first member mounted for gyratory motion, a second member mounted for rotation relatively to said first member and in rolling engagement with said iirst member and electromagnetic means for imparting gyratory motion to said first member to produce relative rotation between said first and second members, characterised in that said electromagnetic means comprise a magnetic circuit of magnetic material constituted in part by said first member, means for generating a unidirectional magnetic ux in said magnetic circuit and a Winding for generating a pulsating magnetic flux in said magnetic circuit and positioned to =be traversed by at least a substantial part of said unidirectional flux.

9. A dynamo-electric device comprising a ilrst member mounted for gyratory motion, a second member mounted for rotation relatively to said iirst member and in rolling engagement with said first member and electromagnetic means for imparting gyratory motion to said iirst member to produce relative rotation between said rst and second members, characterised in that said electromagnetie means comprise a magnetic circuit of magnetic material constituted in part by said first member, a permanent magnet for generating a unidirectional magnetic flux in said magnetic circuit and a winding for generating a pulsating magnetic flux in said magnetic circuit and positioned to be traversed by at least a substantial part of said unidirectional flux.

10. A dynamo-electric device according to claim 9, wherein said first member constitutes said permanent magnet.

11. A dynamo-electric device comprising a rst member mounted for gyratory motion, a second member mounted for rotation relatively to said first member and in rolling engagement with said rst member and electromagnetic means for imparting gyratory motion to said iirst member to produce relative rotation between said first and second members. said electromagnetic means comprising a yoke of magnetic material at least partly surrounding said first member, a plurality of pole pieces of magnetic material projecting inwardly from said yoke towards said iirst member, a. winding upon at least one of said pole pieces for generating a pulsating magnetic iield in said yoke and pole pieces and a permanent magnet for causing unidirectional magnetic flux to traverse, in series, said first member, said pole pieces and said yoke.

ALBERT ERNEST ADAMS. DMITRI WALOFF.

REFERENCES CITED The following references are oi' record in the tile of this patent:

' UNITED STATES PATENTS Number Name Date 511,560 Tesla Dec. 26, 1893 1,862,356 Warren June '7, 1932 2,393,045

Hotchner Jan. 15, 1946 

